🧩 Type Challenges: Advanced Type Puzzles

🎯 Introduction

Welcome to the ultimate TypeScript type challenge arena! 🎉 This tutorial presents a series of increasingly complex type puzzles that will push your type-level programming skills to their limits. These challenges are inspired by real-world scenarios and will teach you to think algorithmically about types.

You’ll discover how to approach complex type problems systematically, break them down into smaller pieces, and build sophisticated type solutions. Whether you’re preparing for technical interviews 🤝, building advanced libraries 📚, or just want to master TypeScript’s type system 🏆, these challenges will elevate your skills to expert level.

By the end of this tutorial, you’ll be solving type puzzles that would stump even seasoned TypeScript developers! Let’s begin the challenge! 🏊‍♂️

📚 Understanding Type Challenges

🤔 What are Type Challenges?

Type challenges are like brain teasers for the TypeScript type system 🧠. Think of them as algorithmic puzzles where instead of manipulating data at runtime, you’re transforming types at compile time to achieve specific goals.

In TypeScript terms, type challenges test your ability to:

✨ Use conditional types to implement complex logic
🚀 Combine mapped types with recursive patterns
🛡️ Handle edge cases and constraint validation
🔄 Think recursively about type transformations

💡 Why Practice Type Challenges?

Here’s why solving type challenges makes you a better TypeScript developer:

Pattern Recognition 🎯: Learn to identify common type manipulation patterns
Problem Decomposition 🧩: Break complex problems into smaller, manageable pieces
Advanced Techniques 🚀: Master sophisticated type-level programming
Error Debugging 🔍: Understand how complex types can go wrong
Interview Preparation 💼: Many companies test advanced TypeScript skills

Real-world application: The patterns you learn here directly apply to building type-safe APIs, form libraries, state management systems, and advanced tooling! 🛠️

🏁 Challenge Level 1: Foundation Puzzles

🎯 Challenge 1.1: Deep Readonly

Problem: Create a utility type that makes all properties of an object deeply readonly, including nested objects and arrays.

// 🎯 Your challenge: Implement DeepReadonly<T>
type DeepReadonly<T> = {
  // Your implementation here
};

// 🧪 Test cases
interface TestObject {
  a: string;
  b: {
    c: number;
    d: {
      e: boolean;
      f: string[];
    };
  };
  g: number[];
}

type Result = DeepReadonly<TestObject>;
// Expected: All properties (including nested) should be readonly

// ✅ Should work
// const test: Result = { a: "hello", b: { c: 1, d: { e: true, f: ["a"] } }, g: [1, 2] };
// ❌ Should fail
// test.a = "world"; // Error: readonly
// test.b.c = 2; // Error: readonly
// test.b.d.f.push("b"); // Error: readonly array

🔍 Solution 1.1

// 🎯 DeepReadonly implementation
type DeepReadonly<T> = {
  readonly [K in keyof T]: T[K] extends object
    ? T[K] extends any[]
      ? readonly T[K] // Keep arrays as readonly arrays
      : DeepReadonly<T[K]> // Recursively make objects readonly
    : T[K]; // Keep primitives as-is
};

// 🎨 Advanced version handling functions and edge cases
type DeepReadonlyAdvanced<T> = {
  readonly [K in keyof T]: T[K] extends (...args: any[]) => any
    ? T[K] // Don't modify functions
    : T[K] extends object
    ? T[K] extends any[]
      ? readonly DeepReadonlyAdvanced<T[K][number]>[] // Make array elements readonly too
      : DeepReadonly<T[K]>
    : T[K];
};

🎯 Challenge 1.2: String Template Literal Parser

Problem: Create a utility type that parses a URL template string and extracts parameter names.

// 🎯 Your challenge: Implement ParseRoute<T>
type ParseRoute<T extends string> = {
  // Your implementation here
};

// 🧪 Test cases
type Route1 = ParseRoute<"/users/:id/posts/:postId">;
// Expected: ["id", "postId"]

type Route2 = ParseRoute<"/api/v1/:userId/comments/:commentId/replies/:replyId">;
// Expected: ["userId", "commentId", "replyId"]

type Route3 = ParseRoute<"/static/content">;
// Expected: []

// 🎯 Bonus: Create a type that generates the params object
type RouteParams<T extends string> = {
  [K in ParseRoute<T>[number]]: string;
};

type Params1 = RouteParams<"/users/:id/posts/:postId">;
// Expected: { id: string; postId: string; }

🔍 Solution 1.2

// 🎯 ParseRoute implementation
type ParseRoute<T extends string> = T extends `${infer _Start}:${infer Param}/${infer Rest}`
  ? [Param, ...ParseRoute<`/${Rest}`>]
  : T extends `${infer _Start}:${infer Param}`
  ? [Param]
  : [];

// 🎨 Alternative approach with better parameter extraction
type ExtractParams<T extends string> = T extends `${infer Before}:${infer Param}${infer After}`
  ? After extends `/${infer Rest}`
    ? [Param, ...ExtractParams<Rest>]
    : [Param]
  : [];

// 🚀 Generate params object type
type RouteParams<T extends string> = {
  [K in ExtractParams<T>[number]]: string;
};

// 🧪 Advanced version with optional parameters
type ExtractParamsAdvanced<T extends string> = T extends `${infer Before}:${infer Param}?${infer After}`
  ? After extends `/${infer Rest}`
    ? [Param?, ...ExtractParamsAdvanced<Rest>]
    : [Param?]
  : T extends `${infer Before}:${infer Param}${infer After}`
  ? After extends `/${infer Rest}`
    ? [Param, ...ExtractParamsAdvanced<Rest>]
    : [Param]
  : [];

🚀 Challenge Level 2: Intermediate Brain Teasers

🎯 Challenge 2.1: Function Composition Type

Problem: Create a utility type that determines the return type of a composed function chain.

// 🎯 Your challenge: Implement Compose<T>
type Compose<T extends readonly any[]> = {
  // Your implementation here
};

// 🧪 Test case functions
declare function fn1(x: number): string;
declare function fn2(x: string): boolean;
declare function fn3(x: boolean): Date;
declare function fn4(x: Date): number[];

// 🎯 Test cases
type Chain1 = Compose<[typeof fn1, typeof fn2]>;
// Expected: (x: number) => boolean

type Chain2 = Compose<[typeof fn1, typeof fn2, typeof fn3, typeof fn4]>;
// Expected: (x: number) => number[]

// 🎮 Bonus: Implement a runtime compose function that matches the type
declare function compose<T extends readonly any[]>(...fns: T): Compose<T>;

// ✅ Usage
const composedFn = compose(fn1, fn2, fn3);
// Should have type: (x: number) => Date

🔍 Solution 2.1

// 🎯 Compose implementation
type Compose<T extends readonly any[]> = T extends readonly [
  (...args: any[]) => infer R
]
  ? (...args: any[]) => R
  : T extends readonly [
      (...args: any[]) => infer R,
      ...infer Rest
    ]
  ? Rest extends readonly [(...args: any[]) => any, ...any[]]
    ? Compose<Rest> extends (...args: any[]) => any
      ? (...args: Parameters<T[0]>) => ReturnType<Compose<Rest>>
      : never
    : never
  : never;

// 🎨 More readable recursive approach
type ComposeChain<T extends readonly any[]> = T extends readonly [
  infer First,
  ...infer Rest
]
  ? First extends (...args: any[]) => infer R1
    ? Rest extends readonly []
      ? First
      : Rest extends readonly any[]
      ? ComposeChain<Rest> extends (...args: any[]) => any
        ? (...args: Parameters<First>) => ReturnType<ComposeChain<Rest>>
        : never
      : never
    : never
  : never;

// 🚀 Advanced version with better error handling
type ComposeSafe<T extends readonly any[]> = T extends readonly []
  ? never
  : T extends readonly [(...args: any[]) => any]
  ? T[0]
  : T extends readonly [
      (...args: any[]) => infer R1,
      (...args: any[]) => infer R2,
      ...infer Rest
    ]
  ? R1 extends Parameters<T[1]>[0]
    ? ComposeSafe<[(...args: Parameters<T[1]>) => R2, ...Rest]>
    : never
  : never;

🎯 Challenge 2.2: Object Key Transformation

Problem: Create a utility that transforms object keys based on a mapping pattern.

// 🎯 Your challenge: Implement KeyTransform<T, M>
type KeyTransform<T, M extends Record<string, string>> = {
  // Your implementation here
};

// 🧪 Test object
interface User {
  firstName: string;
  lastName: string;
  emailAddress: string;
  phoneNumber: string;
}

// 🎯 Transformation mapping
type SnakeCaseMap = {
  firstName: "first_name";
  lastName: "last_name";
  emailAddress: "email_address";
  phoneNumber: "phone_number";
};

type TransformedUser = KeyTransform<User, SnakeCaseMap>;
// Expected: {
//   first_name: string;
//   last_name: string;
//   email_address: string;
//   phone_number: string;
// }

// 🚀 Bonus: Create a reverse transformation
type ReverseMap<M extends Record<string, string>> = {
  [K in keyof M as M[K]]: K;
};

type CamelCaseMap = ReverseMap<SnakeCaseMap>;
type OriginalUser = KeyTransform<TransformedUser, CamelCaseMap>;
// Should restore original User interface

🔍 Solution 2.2

// 🎯 KeyTransform implementation
type KeyTransform<T, M extends Record<string, string>> = {
  [K in keyof T as K extends keyof M ? M[K] : K]: T[K];
};

// 🎨 ReverseMap implementation
type ReverseMap<M extends Record<string, string>> = {
  [K in keyof M as M[K]]: K;
};

// 🚀 Advanced version with partial mapping support
type KeyTransformPartial<T, M extends Partial<Record<keyof T, string>>> = {
  [K in keyof T as K extends keyof M 
    ? M[K] extends string 
      ? M[K] 
      : K 
    : K]: T[K];
};

// 🔥 Utility for automatic snake_case conversion
type ToSnakeCase<S extends string> = S extends `${infer T}${infer U}`
  ? `${T extends Capitalize<T> ? '_' : ''}${Lowercase<T>}${ToSnakeCase<U>}`
  : S;

type SnakeCaseKeys<T> = {
  [K in keyof T as ToSnakeCase<string & K>]: T[K];
};

// 🧪 Test automatic conversion
type AutoSnakeUser = SnakeCaseKeys<User>;
// Automatically converts: firstName -> first_name, emailAddress -> email_address

🧙‍♂️ Challenge Level 3: Expert-Level Puzzles

🎯 Challenge 3.1: Type-Safe SQL Query Builder

Problem: Create a type system for a SQL query builder that enforces correct column references and relationships.

// 🎯 Your challenge: Build a type-safe query system
interface Schema {
  users: {
    id: number;
    name: string;
    email: string;
    age: number;
  };
  posts: {
    id: number;
    title: string;
    content: string;
    userId: number;
    published: boolean;
  };
  comments: {
    id: number;
    content: string;
    postId: number;
    userId: number;
  };
}

// 🎯 Implement these utility types
type Select<T extends keyof Schema, K extends keyof Schema[T]> = {
  // Your implementation here
};

type Where<T extends keyof Schema, K extends keyof Schema[T]> = {
  // Your implementation here
};

type Join<T1 extends keyof Schema, T2 extends keyof Schema> = {
  // Your implementation here
};

// 🧪 Usage examples that should be type-safe
type UserQuery = Select<"users", "name" | "email">;
// Expected: { name: string; email: string; }

type PostWithUser = Join<"posts", "users">; // posts.userId = users.id
// Expected: Combined type with proper relationships

// 🚀 Bonus: Implement QueryBuilder class
declare class QueryBuilder<T extends keyof Schema> {
  select<K extends keyof Schema[T]>(...columns: K[]): QueryBuilder<T>;
  where<K extends keyof Schema[T]>(column: K, value: Schema[T][K]): QueryBuilder<T>;
  join<U extends keyof Schema>(table: U, condition: JoinCondition<T, U>): QueryBuilder<T>;
  execute(): Promise<Select<T, /* selected columns */>[]>;
}

🔍 Solution 3.1

// 🎯 Type-safe query builder implementation
type Select<T extends keyof Schema, K extends keyof Schema[T]> = Pick<Schema[T], K>;

type Where<T extends keyof Schema, K extends keyof Schema[T]> = {
  [P in K]: Schema[T][P] | ((value: Schema[T][P]) => boolean);
};

// 🎨 Advanced join type with relationship inference
type Join<T1 extends keyof Schema, T2 extends keyof Schema> = Schema[T1] & {
  [K in keyof Schema[T2] as `${string & T2}_${string & K}`]: Schema[T2][K];
};

// 🚀 Foreign key constraint validation
type ForeignKeyConstraint<T1 extends keyof Schema, T2 extends keyof Schema> = {
  [K1 in keyof Schema[T1]]: {
    [K2 in keyof Schema[T2]]: Schema[T1][K1] extends Schema[T2][K2] 
      ? `${string & K1} = ${string & K2}` 
      : never;
  }[keyof Schema[T2]];
}[keyof Schema[T1]];

type JoinCondition<T1 extends keyof Schema, T2 extends keyof Schema> = 
  ForeignKeyConstraint<T1, T2> | ForeignKeyConstraint<T2, T1>;

// 🔥 Complete QueryBuilder with type state tracking
interface QueryState {
  table: keyof Schema;
  selectedColumns: any;
  joinedTables: any;
}

type QueryBuilder<TState extends QueryState> = {
  select<K extends keyof Schema[TState['table']]>(
    ...columns: K[]
  ): QueryBuilder<{
    table: TState['table'];
    selectedColumns: K;
    joinedTables: TState['joinedTables'];
  }>;
  
  where<K extends keyof Schema[TState['table']]>(
    column: K,
    value: Schema[TState['table']][K]
  ): QueryBuilder<TState>;
  
  join<U extends keyof Schema>(
    table: U,
    condition: JoinCondition<TState['table'], U>
  ): QueryBuilder<{
    table: TState['table'];
    selectedColumns: TState['selectedColumns'];
    joinedTables: TState['joinedTables'] & Record<U, true>;
  }>;
  
  execute(): Promise<
    TState['selectedColumns'] extends keyof Schema[TState['table']]
      ? Pick<Schema[TState['table']], TState['selectedColumns']>[]
      : Schema[TState['table']][]
  >;
};

// 🧪 Usage example
declare const query: QueryBuilder<{
  table: 'users';
  selectedColumns: never;
  joinedTables: {};
}>;

const result = query
  .select('name', 'email')
  .where('age', 25)
  .execute(); // Promise<{ name: string; email: string; }[]>

🎯 Challenge 3.2: Advanced State Machine Types

Problem: Create a type system for a finite state machine with type-safe transitions.

// 🎯 Your challenge: Implement StateMachine<T>
interface TrafficLightStates {
  red: {
    timer: number;
  };
  yellow: {
    timer: number;
    previous: "red" | "green";
  };
  green: {
    timer: number;
    pedestrianWaiting: boolean;
  };
}

interface TrafficLightTransitions {
  red: ["yellow"];
  yellow: ["red", "green"];
  green: ["yellow"];
}

// 🎯 Implement these types
type StateMachine<TStates, TTransitions> = {
  // Your implementation here
};

type ValidTransition<
  TState extends keyof TTransitions,
  TNextState,
  TTransitions> = {
  // Your implementation here
};

type StateTransitioner<TStates, TTransitions> = {
  // Your implementation here
};

// 🧪 Test cases
type TrafficLight = StateMachine<TrafficLightStates, TrafficLightTransitions>;

// Should allow valid transitions
type ValidRedToYellow = ValidTransition<"red", "yellow", TrafficLightTransitions>;
// Expected: true

type InvalidRedToGreen = ValidTransition<"red", "green", TrafficLightTransitions>;
// Expected: false

// 🚀 Bonus: Runtime state machine with type safety
declare class RuntimeStateMachine<TStates, TTransitions> {
  constructor(initialState: keyof TStates, stateData: TStates[keyof TStates]);
  
  transition<
    TCurrentState extends keyof TStates,
    TNextState extends keyof TStates>(
    from: TCurrentState,
    to: ValidTransition<TCurrentState, TNextState, TTransitions> extends true 
      ? TNextState 
      : never,
    newData: TStates[TNextState]
  ): void;
  
  getCurrentState(): keyof TStates;
  getStateData<T extends keyof TStates>(): TStates[T];
}

🔍 Solution 3.2

// 🎯 State machine type implementation
type StateMachine<TStates, TTransitions> = {
  states: TStates;
  transitions: TTransitions;
  currentState: keyof TStates;
  stateData: TStates[keyof TStates];
};

// 🎨 Transition validation
type ValidTransition<
  TState extends keyof TTransitions,
  TNextState,
  TTransitions> = TTransitions[TState] extends readonly any[]
  ? TNextState extends TTransitions[TState][number]
    ? true
    : false
  : false;

// 🚀 State transitioner with type constraints
type StateTransitioner<TStates, TTransitions> = {
  [TCurrentState in keyof TStates]: {
    [TNextState in keyof TStates]: ValidTransition<
      TCurrentState,
      TNextState,
      TTransitions> extends true
      ? (currentData: TStates[TCurrentState], newData: TStates[TNextState]) => void
      : never;
  };
};

// 🔥 Advanced version with transition guards and effects
type TransitionWithGuards<TStates, TTransitions> = {
  [TCurrentState in keyof TStates]: {
    [TNextState in keyof TStates]: ValidTransition<
      TCurrentState,
      TNextState,
      TTransitions> extends true
      ? {
          guard?: (state: TStates[TCurrentState]) => boolean;
          effect?: (
            from: TStates[TCurrentState],
            to: TStates[TNextState]
          ) => void;
          transform?: (
            currentState: TStates[TCurrentState]
          ) => TStates[TNextState];
        }
      : never;
  };
};

// 🧪 Complete runtime implementation with type safety
class RuntimeStateMachine<TStates, TTransitions> {
  private currentState: keyof TStates;
  private stateData: any;

  constructor(
    initialState: keyof TStates,
    initialData: TStates[typeof initialState]
  ) {
    this.currentState = initialState;
    this.stateData = initialData;
  }

  transition<
    TCurrentState extends keyof TStates,
    TNextState extends keyof TStates>(
    to: ValidTransition<TCurrentState, TNextState, TTransitions> extends true
      ? TNextState
      : never,
    newData: TStates[TNextState]
  ): void {
    // Runtime validation would go here
    this.currentState = to;
    this.stateData = newData;
  }

  getCurrentState(): keyof TStates {
    return this.currentState;
  }

  getStateData<T extends keyof TStates>(): T extends typeof this.currentState
    ? TStates[T]
    : never {
    return this.stateData;
  }
}

// 🎮 Advanced state machine with event-driven transitions
type EventDrivenStateMachine<TStates, TEvents, TTransitions> = {
  handleEvent<TEvent extends keyof TEvents>(
    event: TEvent,
    payload: TEvents[TEvent]
  ): keyof TStates;
};

🏆 Challenge Level 4: Master-Level Puzzles

🎯 Challenge 4.1: Type-Level Parser Combinator

Problem: Implement a parser combinator system that works entirely at the type level.

// 🎯 Ultimate challenge: Type-level parsing
type Parser<T, TResult> = T extends string ? TResult : never;

// Your challenge: Implement these parser combinators
type ParseChar<T extends string, TChar extends string> = {
  // Parse a single character
};

type ParseString<T extends string, TPattern extends string> = {
  // Parse a literal string
};

type ParseDigit<T extends string> = {
  // Parse a single digit (0-9)
};

type ParseNumber<T extends string> = {
  // Parse a complete number
};

type ParseSequence<T extends string, TParsers extends any[]> = {
  // Parse a sequence of patterns
};

type ParseAlternative<T extends string, TParsers extends any[]> = {
  // Parse one of several alternatives
};

// 🧪 Test cases
type ParsedChar = ParseChar<"abc", "a">;
// Expected: { result: "a"; remaining: "bc"; }

type ParsedString = ParseString<"hello world", "hello">;
// Expected: { result: "hello"; remaining: " world"; }

type ParsedNumber = ParseNumber<"123abc">;
// Expected: { result: 123; remaining: "abc"; }

// 🚀 Bonus: Parse a simple expression language
type ParseExpression<T extends string> = 
  ParseNumber<T> | ParseSequence<T, [ParseNumber, ParseChar<"+", "+">, ParseNumber]>;

type MathExpr = ParseExpression<"2+3">;
// Expected: { result: [2, "+", 3]; remaining: ""; }

🔍 Solution 4.1

// 🎯 Type-level parser combinator implementation
type ParseResult<TResult, TRemaining extends string> = {
  result: TResult;
  remaining: TRemaining;
};

// 🎨 Character parser
type ParseChar<T extends string, TChar extends string> = T extends `${TChar}${infer Rest}`
  ? ParseResult<TChar, Rest>
  : never;

// 🎯 String parser
type ParseString<T extends string, TPattern extends string> = T extends `${TPattern}${infer Rest}`
  ? ParseResult<TPattern, Rest>
  : never;

// 🔢 Digit parser
type Digits = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9";
type ParseDigit<T extends string> = T extends `${infer Digit}${infer Rest}`
  ? Digit extends Digits
    ? ParseResult<Digit, Rest>
    : never
  : never;

// 🚀 Number parser (recursive)
type ParseNumberHelper<T extends string, TAcc extends string = ""> = 
  T extends `${infer Digit}${infer Rest}`
    ? Digit extends Digits
      ? ParseNumberHelper<Rest, `${TAcc}${Digit}`>
      : TAcc extends ""
        ? never
        : ParseResult<TAcc, T>
    : TAcc extends ""
      ? never
      : ParseResult<TAcc, T>;

type ParseNumber<T extends string> = ParseNumberHelper<T>;

// 🎭 Sequence parser
type ParseSequence<T extends string, TParsers extends any[]> = TParsers extends [
  infer First,
  ...infer Rest
]
  ? First extends (input: T) => infer FirstResult
    ? FirstResult extends ParseResult<infer FirstValue, infer Remaining>
      ? Rest extends any[]
        ? ParseSequence<Remaining, Rest> extends ParseResult<infer RestResults, infer FinalRemaining>
          ? ParseResult<[FirstValue, ...RestResults], FinalRemaining>
          : never
        : ParseResult<[FirstValue], Remaining>
      : never
    : never
  : ParseResult<[], T>;

// 🔄 Alternative parser
type ParseAlternative<T extends string, TParsers extends any[]> = TParsers extends [
  infer First,
  ...infer Rest
]
  ? First extends (input: T) => infer FirstResult
    ? FirstResult extends never
      ? Rest extends any[]
        ? ParseAlternative<T, Rest>
        : never
      : FirstResult
    : never
  : never;

// 🧙‍♂️ Advanced: Whitespace-aware parser
type SkipWhitespace<T extends string> = T extends ` ${infer Rest}`
  ? SkipWhitespace<Rest>
  : T extends `\t${infer Rest}`
  ? SkipWhitespace<Rest>
  : T extends `\n${infer Rest}`
  ? SkipWhitespace<Rest>
  : T;

type ParseToken<T extends string, TPattern extends string> = 
  ParseString<SkipWhitespace<T>, TPattern> extends ParseResult<infer Result, infer Remaining>
    ? ParseResult<Result, SkipWhitespace<Remaining>>
    : never;

// 🎮 Expression parser with operator precedence
type ParseFactor<T extends string> = ParseNumber<SkipWhitespace<T>>;

type ParseTerm<T extends string> = ParseSequence<T, [
  ParseFactor,
  ParseAlternative<"*" | "/", ["*", "/"]>,
  ParseTerm
]> | ParseFactor<T>;

type ParseExpression<T extends string> = ParseSequence<T, [
  ParseTerm,
  ParseAlternative<"+" | "-", ["+", "-"]>,
  ParseExpression
]> | ParseTerm<T>;

🎓 Key Takeaways

You’ve conquered the most challenging TypeScript type puzzles! Here’s what you’ve mastered:

✅ Complex conditional type logic with nested recursion 💪
✅ Advanced template literal type manipulation for parsing 🛡️
✅ Sophisticated mapped type transformations with constraints 🎯
✅ Type-level algorithm implementation using recursive patterns 🐛
✅ Real-world type system design for complex domains 🚀
✅ Debugging skills for complex type errors and edge cases ✨

Remember: These advanced patterns form the foundation of the most sophisticated TypeScript libraries and tools! 🤝

🤝 Next Steps

Congratulations! 🎉 You’ve mastered the most advanced type challenge patterns!

Here’s what to do next:

💻 Apply these patterns to real projects and libraries
🏗️ Contribute to open-source TypeScript projects using advanced types
📚 Explore the TypeScript compiler source code to see these patterns in action
🌟 Create your own type challenge library for the community!
🔍 Investigate TypeScript’s experimental features for cutting-edge patterns
🎯 Practice with type-challenges.github.io for more puzzles

Remember: You’ve now reached the pinnacle of TypeScript type-level programming! Use these skills to build incredible developer experiences. 🚀

Happy type puzzle solving! 🎉🚀✨

Prerequisites

What you'll learn